Low complexity MMSE precoding and decoding for Multiuser MIMO

Precoding and decoding for Multiuser MIMO has drawn many researchers´ attention. Block Diagonolization (BD) is a competition algorithm for its low-complexity. BD algorithms usually uses the Zero-Forcing criterion, so the performance degrades especially when the noise is strong. The consideration of noise leads to the MMSE criterion. But for multiuser MIMO, there are no methods implementing MMSE both at Tx and Rx yet. This paper proposes an MMSE approach which implements the linear MMSE criteria both at Tx end and Rx end. The proposed algorithm brings the negligible complexity increase compared with the ZF based BD algorithms but outperforms them.